Direct-current machine.



C. W. GIRVIN.

DIRECT CURRENT MACHINE. A PPPP cA' 111111111111111111 3.

I 1,139,203. a I Patented May11,1915. V I I 1 3 SH 5 1.

* "kiwi-Elfin UUUUUU B QEE U WITNESSES I INVEN TOR C. W. GlRVlN.

DIRECT CURRENT MACHINE.

APPLICATION FILED MAY 14. 1913.

1,139,203. Patntd May 11, 1915.

3 SHEETS- SHEET 2.

ETUEU U U QfiUQ% ETD Emmi-Ba m UUEJUGU mmpmgg FIG. 2.. 0)

g INVEHTOR WITNESSES A TTURNEY C. W. GIRVIN.

DIRECT CURRENT MACHINE.

APPLHIATION FILED MAY 14. 1913.

Patented May 11, 1915 3 SHEETS-SHEET 3- El mgm CHARLES W. GIRVIN, OF SAN FRANCISCQLCALTFORNIA, ASSlTGNOR T GIB'VIN ELECTRIC DEVELOPMENT :coMreNY, LIMITED, or nononunu, macaroni? OF HAWAI 7,; A COBPORAQION OF THE TERRITORY HAWAII.

To all whom it may concern;

Be it known that I, Oneness W. Garvin,

a citizen 'of the United States, and residing at San Francisco, in the county of San Fran- 5 cisco and State of California, haye invented certain new and uwful Improvements in lowing is'a specification.

.Direct-Current Machines, of which the fol- This'invention relates to improvements in lOfdirect current machines, viz. machines for generatmg or employing-direct or continu- 'ousnurrents, and more particularly to machines dealing with continuouscurrents of relatively high potential.

" The present invention is a carrying for ward-of the generalidea' disclosed" in my application filed March 11, 1912, Serial No. $83,065, which general idea involvesthe use of open circuit armature coil units maintained constantly in series relationship through a commutator, the latter also main-' taining theunits constantly in circuit, each unit being commutated individually. The general arrangement for providing this result disclosed in said prior apphcationis that of a stationary armature and rotating" fieldmagnet which may be along the lines of a olyphase alternating current synchronous gene rator ormotor, the windings,

I coil-units having their terminals in the id I of brushes adapted to coiiperate with circumferential rows of segments on the commuta- ,tor', these segments being also arran ed approximately in longitudinal rows, t e connections between segments extending gen.-

orallylongitudinally *of the commutator. This arrangement of segments and their I 7 connections is more fully pointed out in my companion a plication filedMay 12, 1913,

40- SeriaYNQ; 76 ,OGQ, but it may be notedthatvthe arran' enient is such that the connections leadi n Y rom segments adapted to cooperalto jivith the brushes of a coil unit are.

, changedin synthronism 'v'vith the reversal of ,45 the E. M. F. of that coil unit, succeeding segments of the circumferential rows havring substantially the sameconnections until the next reversal takes place, these connec- 'tionsbeing so arranged that the alternations I f in direction-of E. in the coil units-are rectified to provide a unidirectional'terminal E. 'M. F. The disclosure in said prior up? plicat'ion provided for various Ways in which Y fl thecui'rent capacity of. the machine may be Specification of Letters Patent. v a ueau nm' a'my s, 1913, semi No. 787,725.

manor-censure .M'acnmn.

PatentedMay 11, 1915.

regulated, as by forming the coil units of a plurality of conductors connected in series, parallel, or combination of both, orb connectin' the terminals of prcdetermine numbers o coil units in series, parallel, or a conr bination of both, the coil units, in the latter the desired current ca acity s of suchla '70 size as to render it di cult to provide the necessary contact area of brushes and segments without unduly enlarging the sizev of the commutator, especially Where each coil unit has individual terminal brushes and but one group is used. And Where a plurality of groups is employed, eachcoil unit of each group having individual terminal brushes, a larger number of leads from the armature is required. These facts do not impair the efiiciency of the machine in operation, any disadvantage that might appear being more particularly in connec tion With the structural designing.- The present invention isdesigned to meet con ditions Where these disadvantages in struc-. tural design may be of importance, the res ent structure embodying features of oth types in that the number of groups is lim: ited, thus decreasing the number of leads, on and at the same time retaining the relativelysmall dimensions of the commutator by'employin a plurality of brushes for each terminal of t e coil unit. Another object is, to H p assisting commutation. 0 these andoth'en ends, the nature of which will be readily und rstood' as the invention is hereinafter 1 disc need, said invention consists in the im. a

rovide means for parts hereinafter described, illustrated in the a companying drawings and more par--.

ticula ly pointed out in the appended claims}; In the accompanying drawings, in which similai referencev characters indicate similar parts in each of the'views,-Figure 1 1 a {developed diagrammatic view of a four ole machine having commutating' poles, the diaments. Fig. 2 is a similar view-showing the.

gram illustrating a group of six coil units having their terminal brushes in connection with a development of a commutator, therefor, the views slibwing the use of two rows of brushes connected in a manner'whereby there is no difference of potential between the brushes on a circumferential row of segusepf four rowscf brushes and thegrnanner of connecting them, the adjacent brushes on a circumferential rowof segments having a difierence of potential. Figs. 3 to 6 inclu sive are developed diagrammatic views showing a fragmentoi Figs. 1 and'2, said views' illustrating various ways in which commutation may be assisted, the views showing the brushes of one coil ,u'nit'knd the brushes of a terminal of another coil unit, together with the brushes of a group terminal,'Fig. 3 showing the arrangement of Figs. 1 and 2 with the brushes indicated as havin left the short-circuit condition,- Fig's. 4 an 5 illustrating ways in whichthe brushes may be displaced to assist commutation, Fig. 6 showing a way of'meetin'g this condition by the use of pilot brushes. ,Fig. 7 is a diagrammatic end view of the commutator and brushes employing the disclosure of Fig. 6. The field magnet poles are indicated at M,

and the coil units are indicated at a, b, 0, d,

e, and f, the commutating poles being indicated at CP. In the drawings I have shown the arrangement as providing a single roup, the conductors generating E. M. F. s o simi lar time values'being connected in series to form the coil units.

. The commutator segments are shown at S.

being assumed to be properly insulatedfron d each other, while the connections between the segments :areindicated by dotted lines,

as atC.

The terminals'ot the coil units are in the form of a connector, the connectors for'coil unit-a being indicated at a and a those for coil unit 22 at b and 12 etc. These connectors in turn are connected to brushes which .are adapted to coeperate with circumferen tial rows of segments in the commutator, the

brushes so connected bein of similar polarity. For instance, in ig. 1, the two brushes with which a single circumferential row of segments cotiperates are positioned to eonmmtateconcurrently and are so located on the row that the connections of the segments on whichthey operate are similar at all times, the result being that theyform divided terminals or terminals in parallel for the coil unit terminal to which they are connected; this permits adjacent connectors,

such as a, a etc, to extend parallel to each without aiiecting the general operation.

/other. By this arrangement, the required brush contact area for the coil unit terminal is distributed between two brushes, thus enabling the use ofjbrushes of smaller size Fig. 2 shows an arrangement similar to Fig.- 1 excepting that two additional rowsof brushes are employed, these brushes interspaced between the rows of Fig. 1; The additional rows are positioned to commutate concurrently with the rows of Fig. 1, but the a location of these brushes is such that the connections of the segments with which they coiipe'rate are bhanged with. respectto the segments otthe brushes fpg Fig. ,1. Adjacent brushes of a coil lfiih't, therefor, which coiiperate' withj'a circumferential row of segments have their segment connections in reverse relati'onship. Consequently adjacent pairs of brushes. coil. unit which cooperate with adjacentfoircum'fere itial rows of segments have the brushes which coeperate with a single circumferential row opposite in polarity, and since the terminal connecbeing spaced apartnn angular. distance equal to the similar distance between-corresponding points on successivepoles, while in Fig. 1 alternaterows are omittedso that thedistasce equals that between corresponding-part of similar poles. Obviously, this arrangement may be employed in connece tion with ,anymultipolar construction the number of rows of brushes connected by connectors such as a, a ,i'ete., not exceeding the number of poles where the commutator 'and rotor travel at the same speed; changes in relative speed causingchanges in this limit. In .otheuwords'g'ftlle number of rows of brushe s which ma r'ovide the arrangementdisclosed here may-equal but not exceed thenumber ofpreversals in connections for any single coil unit. It will be readily understood, however, that the number of rows may be decreased to any desired extent, the minimum limit being two rows,such minimumii jbeing that where a bipolar construction'is employed; this enables the employment offany desired number of rows within these limits, as for instance, an eight pole structure could employ two, three, four, five, six, seven or eight rows,it being understood that the brushesconnected by the connectors are those of similar polarity. One of the principal advantages of this arrangement is that it enables the use of smaller individual brushes thereby permitting" the u'se'of a=commutator of less length without afiecting the diameter. An-

.. pther 'feature lies in the fact that the disunits to the connectors.

' ablement of one brush does not disable the entire machine, the remaining brushes taking up the work under such circumstances. Another feature lies in the fact that a smaller number of groups may be employed,

it being. possible to employ but a single group thus diminishing the number of leads from the armature. Another advantage of this type of construction lies in the ability n to readily provide aids to commutation, some of which are disclosed in Figs. 4 to 7 a of the drawings, the arrangements of these figures being now described and more particularly compared with the arrangement of Fig. 3, the latter diagrammatically representing the arrangement shown in Fig.1, the brushes, however, being Zshown ina dif.

ferent position in Fig. -3, this position beingw one in which the brushes'are assumed'to' have been just-released from short-circuit.

For thepurpose of more clearly explaining.

. 1 the arrangement, I have indicated the row v of brushesat the left in Fig. 3 as 10, and

80 period at the same instant, thus tending to break the short-circuit abruptly.

short-circuit after the release of the brushes 10, thus tending to provide a gradual break: ing of the short-cirouit of the coil unit by reason of decrease of brush contact area, in the short-circuit.

1n Fig/5 I have'shown ,an amplification of the arrangement shown in Fig. 4 in that the connectors (i 0 and b. are shown as provided with resistances indicated at, 1;, 5 these resistances being located in that portion of the connectors between the brushes 15 and the point of'connection of the coil Figs. 6 and 7 indicate a slightlydifierent arrangement from the disclosure of. Fig. 5

in that the row of brushes 15 is not'displaced but additional brushes 20am ositioned to provide the effect of the displaced portion (the heel) \ofthebrushes 15 5 These particiilar arrangements, and'more particularly. thatshownin Fig. .4 is es ecially applicable where-a multi lenum er of rows of brushes is employed,-t e rows be ing picferably displaced in suchmanner as to provide the equivalent-of a 'step-by-s'tep.

increasing of resistance in the. short-circuit} the last row acting to break the short-cir cuit. By this arrangement the action is a gradual one, the final breaking being at the 5 time when the short-circuitfcurrent has alternating E. M'.F,,"a rotatable commutator for rectifying thecunrent of'said sources inl :3? dividually, each terminal of a source 00-,

practically been dissipated by the successive breakings at the other rows.

'Aswill be readily unders'tood;'the number of groups which-may beemployed may depend on individual preference or the use to which the machine is to be put, for instance,

two: groups may be employed with terminals "so arranged as to b'e'placed in series or parallel relation, or four groups may be employed with the terminals arranged to be '75 I connected in series, parallel-series, or parallel. This latter arrangement is desirable for railway work. For instance, by, employing two motors, each having a commutator with twogroups with the terminals adapted to be connected up in the manners indicated various running speeds can be provided by connecting all of the groups in series, orin parallel-series, or in straight parallel. 'This arrangement of-four groups 86 is also made advantageous by reasonof the fact that the general arrangement would permit of the employment of commutators for each motor, each commutator acting for i a single group; if the arrangement for each 90 groupbe along the lines of Fig. 1, difl'erence of potential between rows of brushes is entirely eliminated.- It will be understood, however, "that all of the coil units of a ma chine may beflconnected into a-single group P y i with thevarious connections arranged as In Fig. at, the brushes 10 are shown aslocated in the same position but in the -ar-; rangement of this figure the brushes 15 have '85'be en displaced so as to be released from several waysin which my invention may be carried intoefi'ect,.itwi1llbereadily understood that changes and modifications therein.

maybe required or desired to meet individ- V ual preferences or the exigencies ofusefand I desire to be understood as reservingthe.v 339 right to make-such changes or modifications in so. far as the same may fall within'th spirit and scope of the invention as l e pressed in the accompanying cla'i'ms., v Having tusdescribedmy inventiomwhat I claim new is:.- I I-L i 1, 31" feet current-mechanism, apredetermined numberbf, open circuit sources of" operating/With thefcommutator at spaced tionship.

terminednumber of open-circuit sources of alternat ng E. M. F.', a rotatable commutator for rectifying the current of said sources in dividually, "each terminal of a; source 00- 1 operating with the commutator at spaced apart points of the commutator, the commutator maintaining said'sources in series relationship, the source terminal points of c0- operation being ifi' parallel relation.

3. In direct current mechanisnna predetermined number of open-circuit sources of alternating E. M. F., a rotatable commutator for rectifying the current-of said sources individually, each terminal of a source cooperating with the commutator at spaced apart points of the commutator, the commutator maintaining said sources in series relationship, the source terminal points of .cooperation being in parallel relationship independent of. the commutator;

, 4.. In direct current mechanism, a predeterminednumber of open circuit armature coil units, each terminal of a coil unit being in the formof a plurality of brushes connected in parallel, and a commutator for.

maintaining said sources constantly inseries relationship through said brushes, the com mutator acting individually on each unit.

5. In direct current mechanism, a predetermined number of 0 en circuit armature coil units, each termina of a coil unit being in the form of a plurality ofbrushes 'connected in parallel, and a commutator for maintaining said sources constantly series relationship through said brushes, the commutator acting individually on each unit, the points of contact of brushes in parallel being spaced apart on the commutator.

6. In direct current mechanism, a predetermined number of open circuit armature coil units, each terminal of a coil unit being in the form of a plurality of brushes connected in parallel, and a commutator 'for maintaining said sources constantlyin series relationship through said brushes, the com- -mutat0r acting individually on each unit, the points of contact 0t brushes in parallel being spaced apart on the commutator circumt'erentially.

7. In direct current mechanism, av predetermined number of open circuit armature coil u'iiits, each terminal of a, coil unit being in the; form of a plurality of brushes connected in paralleh and a commutator for maintaining said sources constantly in series relationship through said brushes, thecommutator acting individually on each unit, the .points of contact of brushes in parallel being spaced apart on the commutator, the locations providing substantially concurrent short-circuiting of the coil unit during E. M. F. reversal.

8. In direct current mechanism, a predetermined number of open-c1rcu1t sources of alternating EQ'M. F., a rotatable commutator for rectifying the current of said sources ind'vidually and maintaining them in series re ationship and-in circuit, said rectification including the short-circuiting of the coil unit during its F. reversal and means forintroducing, resistance into the shortcircuit of said unit as its shortcircuiting action progresses.

9. In direct current mechanism, a predetermined number of open-circuit sources of alternating E. M. F., a rotatable commutator for rectifying the' current of said sources individually and maintaining them in series relationship and in circuit, said rectification including the short-circuiting of the coil unit during its E. M. F. reversal and meansfor introducing resistance into the short-circuit of said unit as its short-circuiting action progresses, said means including brushes connected in parallel and acting as a terminal of the unit. v

10. In direct current mechanism, a predetermined number of open-circuit sources of alternating E. M. E, a rotatable commutator for rectifying the current of said sources individually and maintaining them in series relationship and in circuit, said rectification including the short-circuiting of thecoil unit during itsE. M. F. reversal and means for introducing resistance into the short-circuit ofsaid unit as its shortcircuiting action progresses, said means including brushesconnected in parallel and acting as a terminal of the unit, said brushes being positioned on the commutator, to provide overlappingbf short-circuit periods.

. 11. In direct current mechanism, a predetermined number of open-circuit sources of alternating E. M. F., a rotatable'commutaindividually and maintaining them in series relationship and in c1rcuit, s'a1d rectification including the short-cir'cuiting. of the coil for introducing resistance'into the short-cirscuit of said unit as its short circuiting action progresses, said means including brushes connected in parallel and act ng as a terminal of the unit, said brushes having substantially concurrent short-circuit periods, one brush completing its period in advance of another brush. I

13. Indirect current mechanism, a pre etermined number of open-circuit sources of alternating E. M. F., a rotatable commute.

tor for rectifying the current of said sources 4 v tor for rectifying the current of said sources individually and, maintaining them in series relationship and in circuit, said rectification including the short-circuiting'of the coil during its E. M. reversaland means for introducing resistance into the short-circuit of sand unit as its short-c rcuiting action progresses, said means including brushes connected in parallel and acting as a terminal of the unit, said brush connections carrying a resistance element.

I 14. In direct current mechanism, a predeincluding the short-cii-cuiting of the coil unit during its E. M. F. reversal and means for introducing resistance into the short-circuit of said unit as its short-circuiting action progresses, said means including brushes connected in parallel and acting'as' a termi- I n'al ofjthe unit, said brushes having substantially concurrent short-circuit periods, fone brush completing its period in advance hf another brush, said brush connections carrying a resistance element. a

In testimony whereof I afiix my signature in presence of two witnesses. E

CHARLES W.; GIRVIN.

Witnesses 1 THEODORE K. BRYANT, HORACE Gr. Snrrz. 

